1. Field of the Invention
The invention is related to microelectromechanical systems (MEMS) devices.
2. Description of the Related Art
In general, microelectromechanical systems (MEMS) devices include very small mechanical elements. The mechanical element is typically capable of some form of mechanical motion and is formed at the micro-scale using fabrication techniques similar to those utilized in the microelectronics industry, such as using lithography, deposition, and etching processes. A MEMS transducer including the mechanical element converts energy between different forms, e.g., electrostatic and mechanical forms. MEMS transducers may be used as both sensors that convert motion into electrical energy (accelerometers, pressure sensors, etc.) and actuators that convert electrical signals to motion (comb drive, micromirror devices, resonators). MEMS devices using capacitive transducers are easy to manufacture and result in low noise and low power consumption sensors and/or actuators.
Typically, a mechanical element of a MEMS device has a geometry that varies with variations in manufacturing process. Abnormalities and defects in these mechanical elements due to variations in manufacturing process may be difficult to detect in the manufactured device. Accordingly, new techniques for monitoring the quality of manufactured MEMS devices are desired.